[PATCH RFC 0/2] Add linux/ppc64 support for Hotspot serviceability agent to read core files

Maynard Johnson maynardj at us.ibm.com
Thu Dec 4 14:27:32 UTC 2014


On 12/04/2014 02:20 AM, Volker Simonis wrote:
> On Wed, Dec 3, 2014 at 7:55 PM, Maynard Johnson <maynardj at us.ibm.com> wrote:
>> On 12/03/2014 12:33 PM, Maynard Johnson wrote:
>>> On 12/03/2014 02:40 AM, Volker Simonis wrote:
>>>> On Tue, Dec 2, 2014 at 9:50 PM, Maynard Johnson <maynardj at us.ibm.com> wrote:
>>>>> In the approximate 10 times that I re-ran my test with the "-XX:-Inline" (sometimes killing it with SIGSEGV to get a core file; sometimes using 'jstack -F'), I twice got an NPE:
>> [snip]
>>>>>
>>>>> java.lang.NullPointerException
>>>>>         at sun.jvm.hotspot.tools.StackTrace.run(StackTrace.java:88)
>>>>>         at sun.jvm.hotspot.tools.StackTrace.run(StackTrace.java:45)
>>>>>             . . .
>>>>>
>>>>> Line 88 in StackTrace.java is
>>>>>
>>>>>     tty.print(" - " + method.externalNameAndSignature() +
>>>>>     " @bci=" + vf.getBCI());
>>>>>
>>>>> I'll work on debugging this.
>>>>>
>>>>
>>>> Yes, that should be fixed. Maybe we need some more checks if 'method'
>>>> and 'vf' are valid.
>>> In fact, I'm consistently seeing the same NPE on x86 when I run the java app with "-XX:-Inline"
>>> and then do 'jstack -F <pid>'. Do you know if there's a bug report open already for this?
>>> The jdk9 source on my x86 system was a couple months (or so) old, so I wanted to see if
>>> this still fails with current upstream code. I refreshed my source tree (via get_source.sh)
>>> and tried to rebuild it, but I got a compile failure.  I imagine someone else is already
>>> working on that.
>> Never mind . . . The compile failure was due to a conflict between a local change I made in
>> one of the files and a change from upstream. I fixed it and the current upstream source builds
>> fine on x86 now. However, the above-mentioned NPE still occurs most of the time.
>>
> 
> That's bad, but that seems to be another issue which should be fixed separately.
> 
> If you have no more changes/addons compared to my last webrev I can
> offer to submit a new request for review on behalf of you so we
> finally get this in.
Yes, please -- and thanks again for all your help.

-Maynard
> We will need on more review from the
> serviceability team and a sponsor who will push the change for us.
> 
> Regards,
> Volker
> 
>> -Maynard
>>>
>>> -Maynard
>>>>
>>> [snip]
>>>
>>
> 



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